^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #include <asm/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * hweightN - returns the hamming weight of a N-bit word
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * @x: the word to weigh
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * The Hamming Weight of a number is the total number of bits set in it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) unsigned int __sw_hweight32(unsigned int w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) w -= (w >> 1) & 0x55555555;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) w = (w + (w >> 4)) & 0x0f0f0f0f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) return (w * 0x01010101) >> 24;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) unsigned int res = w - ((w >> 1) & 0x55555555);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) res = (res + (res >> 4)) & 0x0F0F0F0F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) res = res + (res >> 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) return (res + (res >> 16)) & 0x000000FF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) unsigned int __sw_hweight16(unsigned int w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) unsigned int res = w - ((w >> 1) & 0x5555);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) res = (res & 0x3333) + ((res >> 2) & 0x3333);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) res = (res + (res >> 4)) & 0x0F0F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return (res + (res >> 8)) & 0x00FF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) unsigned int __sw_hweight8(unsigned int w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) unsigned int res = w - ((w >> 1) & 0x55);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) res = (res & 0x33) + ((res >> 2) & 0x33);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return (res + (res >> 4)) & 0x0F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) unsigned long __sw_hweight64(__u64 w)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #if BITS_PER_LONG == 32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return __sw_hweight32((unsigned int)(w >> 32)) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) __sw_hweight32((unsigned int)w);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #elif BITS_PER_LONG == 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) w -= (w >> 1) & 0x5555555555555555ul;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) w = (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) w = (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return (w * 0x0101010101010101ul) >> 56;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) __u64 res = w - ((w >> 1) & 0x5555555555555555ul);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) res = res + (res >> 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) res = res + (res >> 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return (res + (res >> 32)) & 0x00000000000000FFul;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }